1. Field of the Invention
This invention relates generally to article handling apparatus, and more specifically to an automatic tray loading and indexing mechanism. The invention has particular application to loading of small, relatively thin articles, such as slide transparencies, into circular trays for holding transparencies.
2. Description of the Prior Art
In recent years, use of slide transparencies as a means of presenting information has increased. At the same time, circular slide trays which hold 80 or 140 slides and projectors which use such trays have come into widespread use. Many slide programs are developed with these facilities in mind, using one or more slide trays filled with prearranged programs of slides.
Hand insertion of slides into one or a small number of slide trays is a tedious, time consuming task. In addition, as the task becomes more repetitive, human error becomes more likely. While hand insertion is still the most available method for small jobs, some slide programs, as, for example, in a company-wide information program for a large company, may be reproduced and distributed in dozens or hundreds of copies. When each program involves hundreds of slides, hand insertion becomes prohibitively expensive in terms of labor; the possibilities of error are also multiplied. An article loading mechanism becomes the only efficient solution.
Article loading mechanisms of various kinds are known in the art. Some have an elevator mechanism for engaging an article and moving it into or out of a compartment or receptacle. These generally have a separate mechanism for indexing the receptacle into which articles are placed and a separate mechanism for loading or unloading the receptacle. Also known is a device for successively loading one or more articles into compartments of a tray having a plurality of adjacent compartments by means of a single member which performs the dual function of loading and indexing, e.g., U.S. Pat. No. 3,727,371. Indexing mechanisms specifically adapted for a slide tray are also known, e.g., U.S. Pat. No. 3,236,113. Although these various mechanisms are known, at present there is no known mechanism which can load small, relatively thin articles, such as slide transparencies, into circular slide trays swiftly and automatically.